Strontium-doped mesoporous silica nanoparticles incorporated in chitosan/alginate biocomposite scaffolds for enhanced bone tissue regeneration

Critical-sized bone damage resulting from traumas, fractures, and tumors, impairs the bone tissues' inherent capacity for self-repair. Conventional therapies could be associated with infection and pain besides demanding additional surgery while being costly. These limitations highlight the paucity of potential unique treatment strategies such as bone tissue engineering. In this study, strontium-doped mesoporous silica nanoparticles (Sr-MSN) were successfully synthesized and incorporated into the chitosan/alginate scaffolds which were then freeze-dried and cross-linked using CaCl2. The physicochemical characteristics of the fabricated scaffolds containing various Sr-MSN contents were investigated using Fourier-transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Energy Dispersive Spectroscopy (EDS). The hydrolytic degradation of the scaffolds was decreased with the increase in the Sr-MSN content while maintaining their water uptake capacity. All fabricated scaffolds showed biocompatibility and Sr-MSN-containing scaffolds showed significantly increased Bone marrow mesenchymal stem cells (BMSCs) cell viability compared to chitosan/alginate scaffold after 72 h. The osteogenic differentiation potential investigations via mineralization assay and alkaline phosphatase enzyme activity indicated that the chitosan/alginate scaffold containing 20% Sr-MSN showed the highest osteogenic differentiation capacity. Overall, bionanocomposite Cs/Alg/Sr-MSN scaffolds integrated with desired physicochemical characteristics, biocompatibility, osteogenic differentiation capacity, and drug delivery potential show promising properties for attaining ideal results for bone repair and regeneration applications.